In a measure of the gulf he now felt existed between the two clubs, the Manchester United manager said he had “hammered home” the importance of “goal difference” at the start of the campaign – after they lost the Premier League title to Manchester City last season on that slimmest of measures – and described Santi Cazorla’s late consolation goal as an “embarrassment” to the scoreline.

United went to the top of the table yesterday as Chelsea could only manage a 1-1 draw at Swansea. Manchester City, their other title rivals, were held 0-0 at West Ham.

Inevitably Robin van Persie scored against his former club and Ferguson applauded the striker’s decision not to then celebrate his goal. “He did the right thing,” he said of Van Persie.

The Arsenal supporters continually barracked Van Persie, who quit the club in the summer in a £24 million move to United, with a series of abusive, tasteless chants and they eventually rounded on the club as well.

United defender Rio Ferdinand said: “He [Van Persie] showed his class which is more than what their fans did.”

Ferguson chose to dwell on the narrowness of the scoreline and his “casual” team. “We lost on goal difference last season and I don’t want that to happen again,” he said.

“We should have scored five or six or maybe even more than that. I’m disappointed by our inability to hammer home the advantage. You look at that scoreline and think it was a close game but it wasn’t.”

Van Persie claimed he did not hear the abuse aimed at him. “They are great fans and I respect them,” he said of the Arsenal supporters, while adding of his decision not to celebrate his goal: “It speaks for itself. I respect the club, players, manager. That is why.”

Arsenal manager Arsène Wenger was furious at the second-half dismissal of Jack Wilshere by referee Mike Dean saying it was “not deserved” and a penalty for handball that was given against his side.

“We always have a penalty against us when we play Manchester United, so we get used to it,” he said. Wayne Rooney wasted the chance to improve United’s goal difference by missing the penalty.